Question

5 We came across the letters while we____up our room.
left
was looking
had gone
were tidying
had forgotten
had left
went

Answer 1

Ответ:

Were tidying.

Answer 2

We came across the letters while we were tidying up our room.

Когда говорим о действии которое произошло в момент какого-то продолжительного действия, то используем past simple + past continuous